Roll stand unit for a continuous reducing mill



Feb. 23, TU v ROLL STAND UNIT FOR A CONTINUOUS REDUCING MILL Filed May 18, 1934 e s 5 'W INVENTOR. .5:

BY- ad 1 r TORNEYS.

Patented Feb. 23, 1937 I ROLL STAND UNIT FOR A ooN'nNUoUs REDUCING MILL Heinrich Stiiting, Witten-on-the -Ruhr, Germany Application May 18, 1934, Serial-No. 726,379

. In Germany May 24, 1933 1 Claim.

This invention relates to a toothed roller frame for rolling mills for reducing tubes to a smaller diameter.

Such rolling mills consist of several passes arranged one behind the other, wherein it is of special importance that the distance from pass to pass should be kept as short as possible. Thus by this means 'the space requirements and the working costs will be reduced and finally this reduction in length presents from the point of view of roller technology the great advantage that the unavoidable thickening of the freely running ends, which occurs between the passes is limited to as small a length of tube as possible.

' From this attempt there has arisen the known combination of a gear'body with two passes. By driving the passes respectively in a right and left hand direction from a common driving body and not interposing beside each pass a special drive, the breadth of the structure may obviously be reduced. Within'the gear body the most varied ln'nds of gearing have been known for transmitting to the shafts'of the rollers the work necessary for the rolling operation.

In one known embodiment there is employed by way of example as the transmission means within the gear body an arcuate arrangement of cone wheels in engagement with one another corresponding in number to the roller shafts to be driven. Pairs of spur wheels connect the spindles of the cone wheels to the roller shafts. Since the planes of diameter of the cone wheels arranged in circular formation lie in the direction of the breadth of the roller frame, and both the cone wheels and also the'spur wheels connected thereto must receive not inconsiderable dimensions owing to considerations of stability and durability, there results in this construction a relatively large breadth dimension and together therewith a large pass pitch.

In another known embodiment there is used as transmission means within the gear body a spur wheel, which is provided on both sides with hyperbolic wheels. These directly drive through a hyperbolic pim'on the roller shafts of both passes which are each connected by the central driving body to a frame. By the series arrangement 'of a spur wheel and 'two hyperbolic gears there results of course a disproportionately large pass pitch; thus, thisarrangement likewise does not correspond to the requirements which are placed upon the breadth of the structure with regard to as large as possible a reduction thereof.

On the other hand, an arrangement is known, which indeed does not comprise the combination wheels arranged of a gear with two passes, but only the combina tion of a toothed roller frame with a pass. In this knownarrangement a circular formation of spur wheels is employed which is mounted in the gear body and which drives a number of spur wheels corresponding to that of the rollers. From the shafts of the latterthe rolle'r shafts are driven by the aid of pairs of cone wheels. By employing the circle formation of toothed wheels, which presents a relatively large diameter and a correspondingly broad bearing and further owing to the pairs of cone wheels mounted beside the circle of toothed wheels there results'a disproportionate breadth of structure of the roller frame concerned, whereby again the distance between the passes turns out to be correspondingly large. In a further embodiment of the said known arrangement a double circle of toothed wheels is employed, which consists in one part of a spur wheel and in the other part of a cone wheel; the drive of the roller shafts occurs from the driven cone wheel pinions by the aid of pairs of spur wheels. This embodiment also proclaims the fact that at that time the importance of a short pass pitch was not yet appreciated.

According to the invention the object sought namely to reduce the breadth of the structure is attained by the use of a gear consisting of spur wheels. These spur wheels are all in engagement with one another and are equal in number to the roller shafts which are to be driven. The pivots of the spur wheels all lie on one circular periphery. Whilst therefore in the known construction the drive was effected by a common circle of spur wheels or a spur wheel, the transmission of the driving motion according to the invention occurs from'a spur wheel to the adjacent spur wheel which is in engagement therewith. This again drives the immediately adjacent spur wheel and so on until the circle is closed. It is therefore merely necessary that the rotary movement be introduced into one of these spur wheels from an external source by a driving wheel in engagement therewith, in order to drive all spur wheels and thus the roller shafts driven thereby.

Since wheels of smaller diameter are under consideration, which in order to run easily do not require by any means as wide a bearing as a large toothed driving wheel arranged in the middle of the group of wheels, the width of structure of the gear according to the invention is very small. In comparison with the known cone in circular formation the economy in structural width is-even quite substantial; the cone wheels lie with the. plane of their diameter in the direction of breadth and already take up thereby a fairly considerable one another and which according to the typeof spur wheel is arranged in one plane, presents therefore the smallest attainable breadth of structure and may, since the principal expanse of this gear lies in one plane, whilst the expanse vertically thereto, that is to say, in the direction of breadth is infinitesimally small, be designated as a plane gear. 1

The number of wheels of this plane gear is identical with the number of rollers to be driven. Therefore, if the roller frame contains two passes for every four rollers, then the plane gear consists of eight spur wheels. In a three roller pass the plane gear is provided with six wheels; in the case of passes with more than four rollers the plane gear would consist of a correspondingly larger number of wheels. Finally, the case may arise where the gear body is intended to serve as means for driving one pass. In this case the number of wheels of the gear will be twice as large as the number of rollers; for driving therefore only half the number of wheels will be employed, whilst the intermediately disposed spur wheels serve as socalled intermediate wheels.

The plane gear according to the invention therefore owing to the arcuate arrangement of its wheels, leaves the inner space within the wheels free. Since the wheels require mounting in a surrounding casing, this latter is likewise designed in arcuate form and'may in its central part be constricted, that is to say, limited in breadth, to such an extent as is consistent with considerations of stability.

The roller shafts are driven by the wheels of v the plane gear., For this purpose the cone wheels known per se are employed but however in a special arrangement, The employment of cone wheels at this point instead of within the gear body is in itself already an advantage, when the aim to be pursued is to limit the breadth of structure to as large an extent as possible. In the gear body the cone wheels must be designed according to the peripheral forces which are set up from the rolling work to be performed by the two passes. If therefore every pass has four rollers, the cone wheels must be designed to accord with eight times the peripheral force, which is required by one roller for driving purposes. According to the invention the cone wheels only serve however for driving one roller shaft each, so that they are accordingly lighter and smaller and more particularly take up less space in regard to breadth. Likewise in regard to the diameter of the roller frame economies may be effected according to the invention by arrangement of the bearings for the roller shafts on both sides of the cone wheel drive. By this means it is possible to bring the bearing arranged on the outer periphery as near as possible to the central point of the casing, whereby the overhung mounting of the cone driving wheel may be avoided.

The drawing shows by way of example one embodiment of the subject-matter of the invention.

In the drawing:-

Fig. 1 shows the mechanism in elevation; and

Fig. 2 is a view partly in section looking from the left of Fig. 1.

The plane gear consists of the spur wheels I the pivots of which lie on the circumference of a circle, and which are all in engagement with one another. The spur wheels I rest on shafts 2,

and for mounting thereof, bearings 3 and 4 are provided. The spindles 2 are provided at their ends with drive cone wheels 5, which are in engagement with the driven cone wheels 6. These latter are mounted on the roller shafts I, which are carried by the bearings 8 and 9, and on the inner ends of which the rollers I0 are secured, which constitute the passes.

The plane gear with the wheels I and the bearings 3 and 4 are surrounded by the casing I I, which is designed in arcuate form having an inner ring space and contains concentric apertures at the centres of the wheels, which alternately lie on one and the other side. These apertures are centred relatively to the borings of the bearings 3 and 4 during manufacture and are of such size, that the wheels I may be inserted therethrough into the casing. These apertures are closed by the wheel casings I2 of the cone wheel gear. With these wheel casings are combined the bearings 8 and 9, so that they together with the roller shafts, their bearings, the driven cone wheel 6 and the rollers II. constitute so-called constructional units. By incorporation and removal of these constructional units the individual rollers may as desired be inserted into or removed from the pass without any trouble. For securing these constructional units, suitably arranged screws are provided, which extend through the casing II and are consequently easily accessible from both sides.

The constructional units I2 which engage with their centerings into the machined apertures of the casing I I may thus, as the drawing shows, be rotated about the central axes of the rollers 2, without the engagement of the cone wheels 5 and 6 undergoing any change. This arrangement, which is known in itself, demonstrates particularly the appropriateness of the constructional design according to the invention. By rotating the constructional units I2 the subsequent adjustment of the passes is effected. Since there is in this case concerned the compensation of a slight difference in the wheels due to wear, it is sufiicient that the securing screws of the constructional units I2 be introduced through apertures of larger diameter, so that thereby a slight play of the constructional units about the axis 2 is provided. Since ,the axis 2 about the radius of the rollers (reckoned to the centre of the pass) is inclined to one of the main axes of the pass, in addition to the intended adjustment of the rollers in a radial direction, a further slight adjustment in an axial direction also occurs on adjusting the pass by rotating the constructional units I2. This latter adjustment may in known manner be compensated for by mounting the bearings 8 in the constructional unit l2 not fixedly as shown in Figure 2, but capable of adjustment in an axial direction. The means employed for this purpose ,(screw thread, adjustable bearing boss and the like) are known. Likewise the bearings 9, which is even more easily accessible by turning the screw securing it, into a certain position necessarily shown in broken lines, the other three constructional units being likewise adjusted relatively to the constructional unit thus secured.

In the arrangement selected the pressure screws l3 contribute towards taking up the roller pressure which occurs and to relieve the load on the fastened screws of the constructional units. Whilst, as a matter of fact, the pressure of the roller acts for example, on the constructional unitin an anti-clockwise direction the adjusting screws secured on the constructional unit exerts a pressure thereon in a clockwise direction. By

correspondingly designing the lever arms it is even possible to bring the forces to equilibrium, that is to say, therefore, to relieve the securing screws of the constructional units completely of all load.

As has already been mentioned above the drive for both passes may be transmitted to any desired wheel I of the plane gear. In Figure 1,.

l5 refers to the driving shaft which through a spur wheel l6 secured thereon, which engages in one of the eight wheels I of the plane gear as shown, drives this latter and together therewith the gear as a whole.

I claim:--

A roll stand unit for a continuous reducing mill. comprising a housing having parallel front and rear walls in close spaced relation, a plurality of cooperating grooved rolls forming a substantially closed pass for the workpiece, the front and rear housing walls having work openings in line with the pass, a carrier for each roll pivotally mounted on one of said housing walls and extending inward toward the pass, a roll spindle mounted in bearings'on each carrier and extending radially of the pivotal axis of the carrier and having the roll mounted on its inner end, a bevel gear for driving each roll mounted on the other housing wall to turn about an axis in alignment with the pivotal airis of the roll carrier, 9. bevel pinion on the outer end of each roll shaft meshing with its bevel. gear, and means for driving said bevel gears at equal speed.

' HEINRICH- STUTING. 

